Drought tolerance and toxicity variation of grass pea (Lathyrus Sativus L.) were studied in the presence and absence of earth element Eu 3+ under the pot-culture condition. The addition of exogenous Eu 3+ increases the survival days (SD) and lowered the stomatal sensitivity of grass pea seedlings under the decreasing soil moisture from -0.2 MPa to -1 MPa, suggesting that Eu 3+ can improve the ability of grass pea seedlings to tolerate drought. But in this case, Eu 3+ is found to significantly inhibit the increase in contents of plant toxicity β-N-oxalyl-L-a, β-diaminopropionic acid (ODAP) level in leaves. Therefore, the results demonstrate that Eu 3+ application is a potential agronomic approach to improve drought tolerance while lowering the toxicity level in grass pea productivity. Drought tolerance and toxicity variation of grass pea (Lathyrus Sativus L.) were studied in the presence and absence of earth element Eu 3+ under the pot-culture condition. The addition of exogenous Eu 3+ increases the survival days (SD) the stomatal sensitivity of grass pea seedlings under the decreasing soil moisture from -0.2 MPa to -1 MPa, suggesting that Eu 3+ can improve the ability of grass pea seedlings to tolerate drought. But in this case, Eu 3+ is found to be significantly inhibit the increase in contents of plant toxicity β-N-oxalyl-La, β-diaminopropionic acid (ODAP) level in leaves. Thus, the results demonstrate that Eu 3+ application is a potential agronomic approach to improve drought tolerance while lowering the toxicity level in grass pea productivity.